From Longman Dictionary of Contemporary Englishfourthfourth1 /fɔːθ $ fɔːrθ/ ●●● S3 W3 adjective coming after three other things in a series in the fourth century her fourth birthday —fourthly adverb
Examples from the Corpus
fourth• Her apartment was on the fourth floor.• Mark is starting fourth grade in the fall.fourthfourth2 ●●● S3 W3 pronoun the fourth thing in a series the fourth of Julyfourthfourth3 noun [countable] HMN¼; one of four equal partsone-fourth/three-fourths → quarter1(1)From Longman Business Dictionaryfourthfourth /fɔːθfɔːrθ/ adjectiveACCOUNTING fourth half/quarter/period the fourth half, quarter etc of the financial yearOrigin fourth1 Old English feortha, from feower “four” 